In many modern electronics applications, it is needed in many applications to convert an analog value to a digital value. For example, it some applications it can be needed to convert a continuous physical quantity (such as a voltage) to digital value that represents the amplitude of the physical quantity. Analog-to-digital converters (ADC's) are electronic devices that provide such a conversion.
One continuing issue in ADCs is the need for calibration. In ADCs, calibration can be used to measure and adjust the relationship between the analog input and the digital output. Specifically, such calibration can be used to correct for non-linearity and improve the accuracy of ADCs. For example, such calibration can be used to compensate for non-linearity that arises out of environmental changes (e.g., temperature changes).
Unfortunately, current techniques for calibration in ADCs lack sufficient accuracy for many demanding applications. For example, in ADCs with high levels of non-linearity, the accuracy of calibration using standard techniques can be insufficient. This can be particularly true for ADCs where the nonlinearity is poorly characterized, as current techniques for calibration of poorly characterized nonlinearities are particularly problematic. Thus, what are needed are improved devices and techniques for the calibration of ADCs.